This proposal is to request support for a Keystone Symposia meeting entitled Malaria: New Approaches to Understanding Host-Parasite Interactions, organized by Patrick E. Duffy and Jean Langhorne, which will be held in Copper Mountain, Colorado from April 11 - 16, 2010. Malaria has entered a new era-a partially effective vaccine may be licensed in the not too distant future, and the genomes of host, parasite and vector are now widely available. Major advances have been made in understanding basic parasite cell biology and fundamental immunology, using rapidly evolving molecular genetic technologies for both host and parasite. Systems biology approaches also offer a new paradigm for interrogating complex host responses to a complex pathogen. Future progress will require greater integration of these technologies to elucidate parasite cell biology, host-parasite interactions, and the specific mechanisms that confer protection in our model systems and in nature. This meeting will bring together these new fields to examine those aspects of host and Plasmodium biology important for understanding immunity and pathogenesis. Opportunities for interdisciplinary interactions will be significantly enhanced by the co-location of this meeting with the Keystone Symposia meeting on Molecular Targets for Control of Vector-Borne Diseases: Bridging Lab and Field Research.